Hi,
I'm in the process of designing the electronics for a toy of sorts, and the client suddenly decides he wants it to also make the familiar scanning sounds of metal detectors, like the audio in this:
That video has two kinds of sound, 0:00-0:08 and 0:09-0:18. Either would be fine, and it's not supposed to respond to actual metal or any other input. The catch is that I need to produce the sound using an 8-bit MCU and a piezo element (or a very small speaker), because I already have those in the system and there's very little room for other components.
Looking at the waveforms with non-expert eye, it seems there's a lot of amplitude changes:
Short, rapidly-decaying clicks with variable distances
Some kind of high-pitched slide-whistle AM signal?
So, how can I go about generating these or similar sounds? Can it be done with the aid of a reasonably small analog circuit of some kind? All the metal-detector-related circuits I could find on Google are for actually detecting metal, not for sound...
Thanks!